1. Technical Field
This invention generally relates to augering systems which remove coal from seams within a hill by boring long, horizontally extending holes into the coal seam using an auger comprising a rotary cutting head and a string of auger flights to convey the cut coal from the coal seam. More particularly, the invention relates to auger flight supports for reducing boring friction to extend the distance the auger system can bore into the hill. Specifically, the invention relates to an augering system that includes a support leg that lies between adjacent auger flights.
2. Background Information
Augering machines powered by internal combustion engines have been used for mining coal from hills containing a coal seam for many years. These augering machines utilize an auger having a cutting head which is advanced horizontally into the coal seam. The auger is usually made up of a series of sections or auger flights having a helical wound flighting, which removably couple together end-to-end to convey the cut coal from the cutting head to a point of discharge outside the hill. The auger flights are rotationally and axially coupled by having a socket at one end and a mating shank on the opposite end. The shank of one auger flight fits into the socket of the next auger flight. A slidable latch pin extends transversely through a hole in the auger flight and into a hole in the shank of the auger flight to be coupled thereto. A release lever permits uncoupling of the auger flights such as when the cutting head is being withdrawn from the bored hole at the completion of the boring. As the string of auger flights is withdrawn, the auger flights are sequentially removed from the auger string by uncoupling and lifting the rearmost auger flight from the auger machine. Pairs of side-by-side cutting heads and augers have been used recently to form a pair of parallel holes in the coal seam to remove a larger volume of coal at once. Each auger is powered by an auger machine which applies axial as well as rotational forces to the augers to force the augers and the cutting heads into the coal seam and to rotate the cutting heads breaking away the material which the augers then convey out of the hole.
There is considerable friction developed between the flighting of the auger flights and the bored holes which requires considerable power from the augering machines, and which reduces the power available to the cutting heads and to convey the cut coal. Attempts have been made to reduce such frictional power losses in auger systems. For example, in U.S. Pat. No. 3,036,821 issued to H. D. Letts, there is disclosed a spider device where bearings are attached between each of the linearly extending augers, and a plurality of legs are attached to the bearings to form a “spider”. The spider somewhat supports the flighting on the bottom of the bored hole so that the flighting does not rub the ground as hard when rotating, thus reducing the power requirements of the auger machine. In U.S. Pat. No. 5,685,382 issued to Deeter, there is disclosed a similar auger support having a plurality of radially extending support legs affixed a bearing housing surrounding a bearing. The drive shank of an auger flight is rotatably supported by the bearing at one end of the auger flight, independently of the support provided by the auger flighting, to reduce wear and tear of the flighting and to reduce frictional drag of the auger flights. Finally, in U.S. Pat. No. Re 24,503 to C. E. Compton, which was originally U.S. Pat. No. 2,751,203, there is disclosed a spider-type support system for an auger mining system. All of these devices, however, fail to solve a number of problems associated therewith.
There is thus, a continuing need for a support device which overcomes a number of problems associated with the prior art.